Welcome to the first resident blog for the original Kings of County!
These blog entries are the combined collaboration of several residents of the Kings County Emergency Department, with guidance from Dr. Jay Khadpe.
Every Monday, a new entry will be submitted which will discuss different issues in medicine. There will be four subjects: Trauma, Politics, Critical Care, and Evidence Based Medicine.
The Trauma blog is a monthly blog that will focus on multiple aspects of trauma, the trauma patient and the management of the patient. For the first couple of entries in this blog we will focus on the trauma bay. That exciting, adrenaline rushing place that can be a seamless work of art or a crazy madhouse, depending on the place and time.
This month we will discuss intravenous fluids in the trauma bay and whether or not permissive hypotension is appropriate.
Permissive Hypotension?
The history of IV fluids in Trauma has a long history and the deleterious effect of aggressive fluid resuscitation is almost as long. In 1918, WB Cannon published The Preventive Treatment of Wound Shock in JAMA, in which he says that too much fluid is harmful. The history continues from there and it was during the Vietnam War that ARDS was being described in trauma patients who received large amounts of crystalloid fluid resuscitation.
During the 1960s, there were a couple of papers, including Wiggers & Shires, that said that large amounts of crystalloid fluids worked with trauma patients. The infusion amount was said to be 3 times as much crystalloid as presumed blood loss. These studies were done with animals and dealt with resuscitation after hemorrhage was controlled. This idea and treatment was established in many institutes and is still being taught in medical school and the treatment for fluid replacement in trauma.
While multiple animal studies over the years showed that animals with delayed resuscitation have less morbidity and mortality, it was not until 1994 that the NEJM published an article by Bickell proving this concept in humans. Since that time multiple papers have come out that have continued to show this concept of permissive hypotension.
In 1996, the military created the Tactical Combat Casualty Care (TCCC) guidelines that outline the best practices in battlefield trauma care. The TCCC guidelines follow the recommendations set out by Bickell in 1994.
Present day, Dr. Ken Maddox of Baylor has been the leading voice in the trauma surgery community for the support of permissive hypotension and the decrease of fluid administration to patients in the trauma bay.
The theory of why permissive hypotension improves outcome is not totally agreed upon. There are three main areas of thought. First, an increase in blood pressure could dislodge a clot and cause rebleeding. Another thought is that increased blood pressure causes loss of more whole blood then people who do not get fluids, and last is the idea of thinning out the blood and causing coagulation problems by decreasing the concentration of clotting factors and platelets.
The Bickell paper seems to be the paper that is most quoted when people are supporting the concept of permissive hypotension. This was a prospective study of almost 600 trauma patients with penetrating torso injuries. The study showed that people who had immediate fluid resuscitation had higher mortality and higher incidence of ARDS, sepsis, renal failure and coagulopathies. Keep in mind this paper only makes a statement about penetrating torso injuries.
In 2011, Haut et al published a paper that looked at prehospital fluids. This paper did an analysis of the National Trauma Data Bank looking retrospectively at patients who either received or did not receive prehospital IV fluids. By using the data bank, Haut et al were able to look at over 750,000 patients and showed there was increased mortality. The authors were only able to use the data point of IV catheter or not and used the words intravenous or IV as markers for IV fluids. I think there is a serious flaw in using this as IV fluids and placing an IV does not mean IV fluids were given. One argument being that this shows the benefits of scoop and run more then the benefits of permissive hypotension.
Other studies and animal studies have continued to show this benefit but also highlight that there is a point where the risks supersede the benefits. Patients with very low MAPs begin to show increased acidosis and morbidity/mortality showing that while permissive hypotension in beneficial there is a breaking point. For the TCCC it is a palpable radial pulse and they recommend small boluses or colloids until radial pulse becomes palpable. There were some animal studies that showed that when MAPs get in the 40s the benefits decrease.
After reading the papers and seeing the time and studies put into trauma patient and fluid resuscitation, I think this shows that fluid resuscitation in trauma patients is complicated. Fluid resuscitation needs to be made into more then just fluid or no fluid. An algorithm or teaching model should be created to take this complexity of fluid resuscitation in trauma patients into account. The idea of permissive hypotension has merit, but does not work for all trauma patients, and the patients it will work for need to be appropriately identified.
The first thing that needs to be done is to identify the type of trauma coming in the door. It is easy to get tunnel vision when a trauma comes in and the excitement and drama of the trauma bay takes over. There is a rush to do the primary survey and get two large bore IVs. The next step is then to absentmindedly hook IV fluids to both of these and they are potentially running wide open. This is done to people with 5 gunshot wounds to the stomach or a small knife wound to the arm. By identifying the type of trauma and realizing there are a variety of different traumas is a big management step as well as a critical first step.
Identify the correct type of trauma is another crucial step. That being said, there are multiple types of trauma that can be broken down in multiple ways, including:
Penetrating vs. Blunt
Torso vs. Extremity
Controlled vs. Uncontrolled
Patients with penetrating extremity injury and little blood may not need fluids or blood if there are no signs of significant blood loss at the scene. Blunt trauma has never been studied well, but unless there is suspicion for uncontrolled hemorrhage, there is no indication for IV fluids.
Permissive hypotension comes in to play when talking about Penetrating Torso injuries with uncontrolled hemorrhage. That’s about it. It has been shown in the above papers and other studies that these patients do better when fluid resuscitation is delayed until surgery and definitive hemorrhage controlled. This could be extended to blunt torso injury with possible uncontrolled hemorrhage, but has not been studied.
Therefore, patients with controlled hemorrhage, extremity injuries, blunt trauma injuries don’t show a benefit with permissive hypotension.
As mentioned, the studies by Wiggers and Shires show benefit of crystalloid fluid for trauma with signs of significant blood loss and controlled hemorrhage.
I think if physicians can realize that trauma fluid resuscitation is more complicated than a clear yes or no, but rather if physicians look at each patient’s individual situation then it would be a big step in the right direction. Below are my recommendations based on what I have read.
Early Fluid Resuscitation?
Uncontrollable hemorrhage: No, unless MAP <50 and then blood
Penetrating torso: No, unless MAP <50 and then blood
Controlled hemorrhage: If necessary, IV fluids and blood
Extremity injury: If necessary, IV fluids and blood
Blunt injury: Varies by individual case.
What are the algorithms or guidelines that you use? Is this something that is mainstream or still new in practice among ED attendings. I would love to hear your thoughts.
mritchie
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Mike makes some great points in this nice review. As he states it is important to get the access early. That way it is there if you need it but that does not mean you HAVE to hang crystaloid. Another important point is to run what ever fluid you are going to use on the Level 1. We just don’t use these machines enough. The large bore tubing along with the built in pressure bags can really load a patient up quick if you need to. Additionally, it gets the fluid nice and warm on the way in because patients don’t only get coagulopathic from dilution but from cold fluid as well. This is real important when giving blood that just came out of the fridge. Remember too that you should not be using those 2mm wide IV attachments that come in the start kit. They are a bottle neck for fluid and will end up killing your patients if you really need fast flow.
I just wanted to point out that I personally would feel very uncomfortable with a MAP in the 50’s and use a target closer to around 65 (same as for EGDT in sepsis). I’ve seen a variety of possible target endpoints using both MAP or SBP, but most seem to be based on animal studies. What BP goal is everyone else using? Also, I wanted to re-emphasize that the best evidence for this concept is in penetrating torso injuries and its role in blunt trauma is not well established and it is contraindicated in traumatic brain injuries- the brain doesn’t seem to like hypotension!
Great review. I am more comfortable with lower MAPs but our trauma surgeons are not. The trauma faculty are often the ones pushing for higher SBPs.
There has become a very strong push to fluid resuscitate all trauma victims regardless of need for fluid resuscitation. I saw a 85 y/o 85 pound lady last week with 16 gauge IVs flowing each arm. Her only injury was a non-bleeding scalp lac. She was being over-resuscitated and was in danger of APE. Now scalp lacs can bleed, but hers was not.
In general we don’t need 2 liters of IVF flowing on most of our patients. I think it is smart to have the access ready, but no need to use it just because it is there. In general, if you really have to have 2 liters of IV crystalloid flowing through a rapid infuser, you should be using blood anyway (in trauma patients).
Here is my suggestion
2 large bore IVs on those that NEED fluid resuscitation
Heplok 1 of the IVs on most patients
Shoot for a target MAP
if you feel like true emergent resuscitation is needed, use cells early.
As a spin off to this there is an article in the NYT today about tranexamic acid and the CRASH-2 trial. Also there was an unfortunate case in CCT yesterday that ended in a thorocotomy and findings of a partially transected aorta. Apparently this is being used in the wars to control hemorrhage. When I reviewed the CRASH-2 trial there was no mention of the types of injuries leading to the hemorrhage ie. transected carotid arteries vs. small paper cut. Anyone have any insight about this?
Thanks for bringning this up Jay. The crash 2 trial looked at all commers to the ED with trauma but only included those who “might” need the tranexemic acid due to possible bleeding. Those who were bleeding and definitely should have gotten it were excluded from the study. Sort of makes sense because how could you randomize someone to possibly not get the drug that has already been proven to work in bleeding elective OR cases. Not giving it to someone who is bleeding would be wrong. Even in patients who “might need it” there was a significant improvement so the thought is that we should definitely be using it in those who are bleeding or are high risk of bleeding. The good news is Sage is working on getting it onto our formulary as we speak. The word is the county higher ups like it because it is a pretty cheap medication. Sounds like a win-win situation.